Normally, Diffie-Hellmain parameters are distributed (and generated) by a central agency agreed upon by participating parties, so a DHParameterGenerator will be invoked far less often than, say, a generator for RSA, DSA (or DH) keypairs.

Parameter generation is also similarly resource intensive: for example, generation of the sample parameters given in Annex D of X9.42 takes about 100 seconds on a Pentium-based JVM.